Can anybody please help me, ok I usually have my mac set up for the display 2 shut off after 1 min. The day b4 I went back use it and it didn't respond, the light from the mouse was still on but it did not do anything. so I turned it off then turned it back on and it worked fine. Today it did the same thing and when i tried 2 turn it back on all i get is a white screen and a loud buzzing sound every 3 sec. please help!